The mission requirement being discussed at the time the shuttle system was being built (as unrealistic as it sounds now) ran as follows. In a time of international tension (this was in the depths of the Cold War, after all) the US discovers the urgent need to deploy a reconnaissance satellite into polar orbit. Tensions are so high that the shuttle may be exposed to ASAT measures, being a much easier target to track than its payload. So they launch south across the Pacific, pop open the payload doors as soon as they reach orbit, deploy the satellite, close doors and hope there isn't a proble, do a deorbit burn, and angle the re-entry path hard to return to Vandenburg.

"A 1973 internal Johnson Space Center document established requirements 3A and 3B for the shuttle. The first requirement was the ability to launch a large payload into polar orbit and return the shuttle to its launch site at Vandenberg Air Force Base in California. The latter required the shuttle to launch into the same orbit and conduct a rapid rendezvous and retrieval of the same payload that would have been launched under requirement 3A. The shuttle then would have returned to the launch site, this time carrying 11,340 kilograms in its payload bay. This is the same mass listed in a declassified document for HEXAGON vehicles 7–12, plus equipment in the shuttle bay for holding the spacecraft. However, a HEXAGON at the end of its mission, with its reentry vehicles and film and fuel expended, would have been considerably lighter."

An interesting feature of BRM-3 is that it specifies an inclination of 104deg which is not sun-synchronous. I have seen a track chart for BRM-3 and in the second half of the single orbit the Shuttle would have passed over the Middle East and Western Europe, just below the horizon of the Soviet spacewatch radars in Azerbaijan and Stevastopol. Clearly this was the reason for choosing this particular orbit. The Soviets didn't have IR launch warning satellites in those days, so the launch might have remained secret from them (unless you believe the rumors about KGB moles living in Lompoc). Since the HEXAGON satellites were short-lived, they didn't need to be sun-synchronous.

BRM-3A might have been practical since all they had to do was open payload bay, eject the satellite, close the bay, and reorient for retrofire. BRM-3B was hopeless right from the start. Whoever drew it up must not have known anything about orbital rendezvous.

Members of Nixon's inner circle claim that some USAF officers convinced him that Shuttle could capture Soviet satellites and that this alleged capability had a major role in approval of the Shuttle program. This story resurfaces from time to time but it makes no sense:

-- Soviet spacecraft were designed to take launch loads in the vertical direction only

-- we wouldn't know how to design the interface hardware

-- we did know that many Soviet military spacecraft had demolition charges on board.

But just because it makes no sense doesn't mean that it wasn't told to Nixon.

An interesting feature of BRM-3 is that it specifies an inclination of 104deg which is not sun-synchronous. I have seen a track chart for BRM-3 and in the second half of the single orbit the Shuttle would have passed over the Middle East and Western Europe, just below the horizon of the Soviet spacewatch radars in Azerbaijan and Stevastopol. Clearly this was the reason for choosing this particular orbit. The Soviets didn't have IR launch warning satellites in those days, so the launch might have remained secret from them (unless you believe the rumors about KGB moles living in Lompoc). Since the HEXAGON satellites were short-lived, they didn't need to be sun-synchronous.

BRM-3A might have been practical since all they had to do was open payload bay, eject the satellite, close the bay, and reorient for retrofire. BRM-3B was hopeless right from the start. Whoever drew it up must not have known anything about orbital rendezvous.

Members of Nixon's inner circle claim that some USAF officers convinced him that Shuttle could capture Soviet satellites and that this alleged capability had a major role in approval of the Shuttle program. This story resurfaces from time to time but it makes no sense:

-- Soviet spacecraft were designed to take launch loads in the vertical direction only

-- we wouldn't know how to design the interface hardware

-- we did know that many Soviet military spacecraft had demolition charges on board.

But just because it makes no sense doesn't mean that it wasn't told to Nixon.

Possible answer to point 1:Wouldn't a payload bay attachment system transfer loads so that a vertical integrated satellite could be mounted and returned in the payload bay?

Possible answer to point 3:If the destruct charges are remote-control only, then one could "grab" the satellite outside of line-of-sight of the Soviet control stations, return to Vandenberg still out of view of the USSR/satellite nations, and the VAFB landing strip is not line of sight either--no "kaboom" on the ground.

(Unless the little old KGB mole lady from Lompoc can trigger the destruct charge from an adjacent mountaintop.)

Further possible answer to point 3:Leave "chaff" behind in captured satellite's orbit--at first glance via Soviet radar, it looks like a ruptured satellite's debris field.

A scenario worthy of Jack Ryan? Or Alfred E Neuman?

EDIT: (I'm not sharing an opinion for/against such a caper--just some thoughts to stir discussion on whether or not it's even plausible circa when STS operations were originally planned to begin at VAFB.)

The really difficult intelligence requirement for STS was the 32,000lb to polar orbit payload. This was the tall pole in the program because a large proportion of the total "payload" orbited was the parasitic mass of the Orbiter. The decline in performance with inclination was proportional to the total orbited mass, but had to be subtracted from the much smaller actual payload.

Even the "production" shuttles didn't come close to meeting this requirement. How close is hard to say because there is surprisingly little data on masses in the shuttle literature. It seems that most of the performance deficit was extra weight in the Orbiters, which got much worse after ~4,000lbs of lead was added to their noses to fix an error in calculating the center of lift.

The USAF tried to fix the problem by A) going to 109% thrust on the SSMEs and B) developing lightweight "filament-wound" SRBs in which most of the steel was replaced by fiberglass. A) never worked and B) didn't work well enough. By 1984 it was clear that the heaviest polar-orbit payloads (KENNEN and LACROS) couldn't be launched and the USAF was forced to break its treaty with NASA and start the CLEV>Titan IV program.

The failure of STS to meet its cost and flight rate targets has gotten a lot of attention but the payload deficiency led directly to the intelligence community dropping its support for the program. Somebody should study this issue. It is mostly ignored in Dennis Jenkins' book.

1. The really difficult intelligence requirement for STS was the 32,000lb to polar orbit payload. This was the tall pole in the program because a large proportion of the total "payload" orbited was the parasitic mass of the Orbiter. The decline in performance with inclination was proportional to the total orbited mass, but had to be subtracted from the much smaller actual payload.

2. Even the "production" shuttles didn't come close to meeting this requirement. How close is hard to say because there is surprisingly little data on masses in the shuttle literature. It seems that most of the performance deficit was extra weight in the Orbiters, which got much worse after ~4,000lbs of lead was added to their noses to fix an error in calculating the center of lift.

3 The USAF tried to fix the problem by A) going to 109% thrust on the SSMEs and B) developing lightweight "filament-wound" SRBs in which most of the steel was replaced by fiberglass. A) never worked and B) didn't work well enough.

4. By 1984 it was clear that the heaviest polar-orbit payloads (KENNEN and LACROS) couldn't be launched and the USAF was forced to break its treaty with NASA and start the CLEV>Titan IV program.

5. The failure of STS to meet its cost and flight rate targets has gotten a lot of attention but the payload deficiency led directly to the intelligence community dropping its support for the program. Somebody should study this issue. It is mostly ignored in Dennis Jenkins' book.

1. That is why the 32klb to 98 degrees was called Performance Reference Mission-4 vs the 65klB due east mission of Baseline Reference Mission-1. BRM-1 drove the structural capabilities of the Orbiter for launch and landing. It did not drive the performance capabilities. That was PRM-4, which if you could launch 32klb to 98degrees meant you could launch 76-77klb to 28.5 degrees.

2. There was no such mass added to the nose of Orbiters. And in actuality, the orbiters were nose heavy. That is the reasons for cargo being placed in the back of the payload bay and for Spacelab to have a long tunnel. When the shuttle flew ballast, it was in the aft part of the payload bay.

3. The USAF had nothing to do with 109% SSME or FWC SRM's. Those were strictly NASA projects and money. And 109% did work but there were reduced margins and 109% was available for aborts. FWC had some risks (due to the stiff SLC-6 launch mount) but it did work

4. No, the CELV program was not started for VAFB missions, but for mission assurance for east coast missions. The requirement was 10klb to GSO and only 10 missions. West Coast Titan IV did not come about until after Challenger. As for LACROS, what flew on STS-27? And there was no "treaty" between NASA and the DOD to be broken.

5. No, the Challenger incident and the removal of payloads not needing a man in the loop is the reason for the DOD leaving.

If I remember correctly, it was the military that demanded the Space Shuttle be capable of returning to base after just 1 orbit, and this capability was never actually used in the history of STS.

How much did this requirement impact the other capabilities and the safety profile of the Space Shuttle? How much better (or worse) would the vehicle have been without this design requirement?

It is commonly stated that large cross range (hence wing design and size) was purely an Air Force demand, and if unburdened from this requirement an alternate design would have been much cheaper and more reliable. In reality the development history was more complex. After a period of debate, NASA also wanted large cross range capability and delta wings for abort and perceived flight safety reasons.

The same reasoning applied to the "large" payload bay. This is often depicted as yet another Air Force stipulation. However one of the shuttle's key mission requirements was building a modular space station. You can't build a modular space station with a little orbiter.

The alleged advantages of an alternate design start building on one another, e.g, if big wings aren't needed, maybe robust metallic tile TPS could be used. However when NASA seriously examined metallic TPS, it had major risks. The slightest scratch of the coating would cause oxidation and a burnthrough. Faget himself was afraid of metallic TPS.

The same reasoning applied to the "large" payload bay. This is often depicted as yet another Air Force stipulation. However one of the shuttle's key mission requirements was building a modular space station. You can't build a modular space station with a little orbiter.

The same reasoning applied to the "large" payload bay. This is often depicted as yet another Air Force stipulation. However one of the shuttle's key mission requirements was building a modular space station. You can't build a modular space station with a little orbiter.

The payload bay was sized for HEXAGON.

There was no space station planned when STS was green-lighted.

Wrong. That was only the length. HEXAGON was only 10ft wise. The diameter of the payload bay was sized fire station modules and high energy upper stage, as stated many times before.